PTFE Needle Felt Filter Bags for Liquid Filtration
PTFE (Polytetrafluoroethylene) needle felt filter bags are widely recognized as premium filtration media for dust collection systems and also play a critical role in liquid filtration applications. Thanks to their exceptional chemical resistance, high-temperature stability, and non-stick surface properties, PTFE filter bags are ideal for demanding filtration processes in the chemical, pharmaceutical, food & beverage, electronics, and water treatment industries. Under ideal conditions, the service life can reach 3–5 years; in actual industrial applications, it may range from 1 to 4 years.
Description
Base Fabric Material – PTFE Needle Felt
PTFE (polytetrafluoroethylene) needle-punched felt, as a flagship filter material in the high-end industrial dust removal field, is a non-woven filter material made of PTFE fiber as the base material and processed through a three-dimensional needle-punching process.
PTFE fibers offer superior resistance across the entire pH range of 1–14. They are virtually unaffected by strong acids, strong alkalis, oxidizing agents, and most organic solvents, making them the preferred choice for highly corrosive liquid filtration environments.
The microporous structure formed by PTFE fibers enables effective removal of suspended solids, fine particles, and contaminants from liquids, resulting in improved product purity and process reliability.
PTFE possesses one of the lowest coefficients of friction among industrial materials. Its smooth, non-stick surface minimizes particle adhesion, facilitates cleaning, and helps maintain stable filtration performance over extended service periods.
PTFE fibers can operate continuously at temperatures up to 240–260°C, making them suitable for high-temperature liquids and aggressive chemical processing applications.
PTFE is chemically inert, non-toxic, moisture-resistant, and electrically insulating. It does not release contaminants into the filtered media, making it suitable for pharmaceutical, food processing, and high-purity chemical applications.
Exceptional anti-aging properties and zero moisture absorption allow for repeated cleaning and backwashing, significantly lowering the Total Cost of Ownership.
Properties of PTFE Needle-Punched Felt
| Weight（gsm） | 750 | |
| Thickness(mm) | 1.5 | |
| Width(m) | ≤2.2 | |
| Finish treatment | Singeing & Calendering, PTFE Impregnation, PTFE Membrane Lamination | |
| Filtration Rating (µm): | 0.5, 1, 3, 5, 10, 25, 50, 80, 100, 125, 150, 200, 300, 400, 600, 800, 1000 | |
| Tensile strength(N/5cm) | warp | ≥700 |
| weft | ≥600 | |
| Tensile elongation(%) | warp | ≤20 |
| weft | ≤30 | |
| Heat shrinkage(%) | warp | ≤1.5 |
| weft | ≤1.0 | |
| Temperature(°C/°F) | Continue | 240 |
| Instant | 260 | |
| Anti-acid | Good | |
| Anti-alkali | Good | |
| Anti-abrasion | Excellent | |
| hydrolysis stability | Middle | |
Common Size (Customizable)
| Model | Diameter(mm) | Length(mm) | Accurate(μm) | Maximum flow(m³/h) | Filter area(㎡) |
| #1 | 180 | 410 | 1-300 | 20 | 0.25 |
| #2 | 180 | 810 | 1-300 | 40 | 0.5 |
| #3 | 102 | 210 | 1-300 | 6 | 0.09 |
| #4 | 102 | 360 | 1-300 | 12 | 0.16 |
| #5 | 152 | 560 | 1-300 | 18 | 0.3. |
Manufacturing Process
Filmedia® offers customized PTFE liquid filter bag solutions in a wide range of sizes, configurations, and filtration ratings to meet the most stringent industrial filtration requirements.
☑ Controllable Filtration Precision
By adjusting the thickness of the needle-punched felt, the filter bags can achieve higher filtration precision, typically delivering a removal rate exceeding 90%.
☑ Surface Post-Treatment
The filter bag surface undergoes singeing, calendering, and membrane lamination processes to effectively prevent fiber shedding (fiber migration).
Ring Materials
Liquid filter bags are available with various collar ring options to meet different housing requirements:
Steel Ring
- Stainless Steel Ring
- Galvanized Steel Ring
Plastic Ring
- Polypropylene (PP) Ring
- Polyethylene (PE) Plastic Ring
Sealing Process
Hot-Melt Welding Process
Employs advanced ultrasonic hot-melt welding technology to ensure superior seam strength and sealing performance, effectively preventing bypass leakage while enhancing filtration efficiency and product reliability.
Stitched Seam Process
Utilizes a high-strength five-thread overlock stitching process for secure, durable seams. Uses specialized sewing thread free of silicone lubricants to avoid the silicone contamination and secondary pollution issues often associated with standard stitched filter bags.
Typical Applications
- Chemical processing
- Fine chemicals production
- Pharmaceutical manufacturing
- Food and beverage processing
- Electronic chemicals filtration
- Acid and alkali solution filtration
- Organic solvent recovery
- High-purity chemical production
- Water and wastewater treatment
- Electroplating and surface treatment
- Petrochemical industry